Various apparatus are available that receive strips of cut material and then manipulate the material strips such as by either or both rotating or pivoting the strips relative to their initial direction of movement and then placing such material strips on or near a continuously moving surface. In placing the strips of material relative to the moving surface, such apparatus generally begin the placement by initially contacting the leading edge of the strip with the moving surface and then progressively laying or rolling the strip upon the surface with the trailing edge of the strip being the last to be laid upon the moving surface.
A problem that exits with these apparatus is that rotation of the transferring element, upon which the strip is carried, can cause the transferring element to bite or dig into the moving surface, thereby undesirably cutting or otherwise damaging the moving surface. For example, as the transferring element releases the leading edge of the material strip and then begins to pivot or rotate upwardly away from the moving surface, the trailing edge of the transferring element pivots or rotates against and into the moving surface. This can either or both damage the moving surface and disrupt the proper positioning or registration of the strip with the moving surface, and is particularly undesirable when the moving surface is a woven or nonwoven material.
This problem is particularly acute when the strip being laid upon the moving surface is of a generally elongate or rectangular shape having its longest axis parallel to the direction of movement of the moving surface.
Another frequently occurring problem in such processing relates to the proper releasing of the strip of material from the transferring element to the moving surface. Generally, such strips of material are held on their respective transferring elements via a vacuum effect created or transmitted through perforations or holes in the outer surface of the transferring element. Unfortunately, these apparatus may not extinguish or otherwise release the vacuum against the strip of material as the strip of material is progressively transferred leading edge to trailing edge on the moving surface. For example, if the vacuum is not progressively extinguished as the strip is progressively laid from the transferring element onto the surface, portions of the strip element can continue to be held by vacuum against the transferring element resulting in an undesirable pleat or fold in the strip material, skewed alignment of the strip material with the moving surface, and the like.
In view of these and other perceived shortcomings in prior existing apparatus and processing relating to the receiving and rotating strips of material and then placing the rotated strips relative to a continuously moving surface, a new applicator apparatus and application process has been developed and is the subject of Pohjola, U.S. Pat. No. 5,104,116, issued Apr. 14, 1992, and Pohjola, U.S. Pat. No. 5,224,405, issued Jul. 6, 1993, the disclosures of each of which is incorporated herein by reference in its entirety. In accordance therewith, a strip of material is received and rotated toward a continuously moving surface, and then orientated so that the surface thereof is placed generally flat with the continuously moving surface via one or more puck rotating means. In accordance with certain preferred embodiments thereof, the apparatus additionally includes a surface-leveling means for positioning the puck surface in an appropriate spaced-apart relationship with the moving surface. To that end, these patents disclose puck assemblies which in addition to rotating, pivot such that the puck surface is placed flat against or with the moving surface, as desired, and such as may employ open cams.
While such apparatus and associated processing has been successful in overcoming, reducing or minimizing at least some of the problems or shortcomings of earlier apparatus and processing, there remains a need for further improvements. In particular, the employment of features such as pivoting plates and open cams have been found to be a major cause of such strip rotation applicator maintenance and delay. Thus, there is a need and a demand for further apparatus and processing improvements such as effective to achieve one or more of the following:
1. reduce or minimize required maintenance, PA1 2. speed processing and PA1 3. reduce or minimize such complications as may be associated with apparatus and processing relying on rotation and pivoting of puck members and the corresponding placement of an associated strip of material with a corresponding continuously moving surface.